The cause of truth and reason in today's global warming debate has received a major boost with the launch of Professor Ian Plimer's book, Heaven and Earth - Global Warming: The Missing Science.

Plimer, who teaches in the School of Earth and Environmental Sciences, University of Adelaide, and is emeritus professor of earth sciences at the University of Melbourne, is one of Australia's best-known geologists with a string of books and scientific papers to his name.

There have been several books published in recent months aimed at countering the barrage of exaggerations, half-truths and outright inaccuracies concerning alleged man-made global warming. So far, few of the politicians, journalists and assorted scientists riding the alarmist bandwagon have been paying attention to the hard scientific facts on climate change, preferring to behave more like religious fanatics.

One hopes this will change with the appearance of Heaven and Earth, for no book I have come across has covered climate science so thoroughly or demolished the science fiction of computer models so tellingly.

The sub-title of Plimer's book, "The Missing Science", indicates that in public discussions very little of the relevant science rates a mention next to the flawed computer model predictions.

Some might think Plimer's geology expertise irrelevant to any discussion of climate change, since everything weather-wise supposedly occurs in the atmosphere where man's "polluting" carbon dioxide emissions are forcing up the world's temperatures at an alarming rate.

In fact, the most reliable information on long-term climate change is to be found in ice cores, peat bogs, ocean sediments and tree rings. These tell us the story of climate change over millions of years, and set the context for today's ever-changing weather and climate.

Computer models, no matter how technically impressive, simply cannot process the countless variables that affect the direction of climate change. Weather forecasts have enough difficulty being accurate over a single week, let alone over decades or centuries.

Plimer, on the other hand, citing vast numbers of scientific findings from around the world, examines in detail the roles played by the sun, the earth, ice, ocean currents, water and air in causing climate changes over millions of years. Next to these vast forces, increasing human emissions of carbon dioxide are puny in the wider scheme of things.

While the topic, of its nature, is complex and technical, Plimer achieves the near impossible in making the information intelligible to the average educated reader.

In any case, throughout his book Plimer relieves his lengthy technical explanations with morsels of humour and satire. For example, regarding the "endangered" polar bears, so dear to Al Gore and his acolytes, he writes:

"Even if polar bears first appeared in the creationist world at 9am on 26 October 4004 BC, they still had to survive at least five periods of global warming before they entered the Late 20th Century Warming."

The following facts, even though they scarcely do justice to Plimer's 500-page book, emerge from this reviewer's reading of Heaven and Earth, and need to be addressed by those alarmists proposing to save us from future climate catastrophes with billions of our tax contributions.

• The earth's recent warming since the mid-19th century is not unprecedented, and quite mild compared with earlier warmings.

• There is no correlation between the amount of CO2 in the atmosphere and temperature. Increases of CO2 follow temperature rises and not vice versa.

• There are numerous natural factors contributing to climate change: fluctuating sun spots, the earth's wobble and varying distances from the sun, ocean currents, clouds, even the solar system's movement through the Milky Way. Next to these, man's increasing emissions of CO2 are an insignificant factor.

• Computer models cannot incorporate the numerous complex factors that influence weather and climate changes. The models failed to predict the recent levelling off and even cooling since 1998, despite the continuing increasing emissions of CO2.

• Sea-level changes can be due to a drop in the ocean floor, volcanoes or rises in parts of the earth's landmass. Current predictions of present or future sea level rises are wildly exaggerated.

• 85 per cent of the earth's active volcanoes - which emit vast quantities of CO2 - are under the oceans and not considered in computer models.

• The Intergovernmental Panel on Climate Change (IPCC), whose claims are cited as "bible truth" by alarmists, is more political than scientific in orientation.

Although large numbers of scientists have contributed to its reports, only a handful assemble the reports, and an even smaller handful - Plimer calls them "The Famous Five" - put the summaries together for the benefit of politicians and media people who usually read no further.

These summaries have put an alarmist "spin" on the conclusions which fail to reflect the thrust of the reports, let alone the scientific contributions.

• There is no scientific "consensus" on man-made climate change. Even if there were, it need not prove anything. There was once a consensus that the sun revolved around the earth.

• Temperature measurements, until the recent use of balloons and satellites, have been grossly unreliable. The surrounds of weather stations have changed over time, including the "heat island" effect due to industrial developments and increased populations.

• In any case, warmer temperatures have proved beneficial for human development. The great achievements of ancient Greece and Rome occurred during a warming period, and the magnificent cathedrals and universities were built during the Medieval Warming (900-1300AD) which saw increases in population and agricultural productivity.

Average temperatures during the Medieval Warming were higher worldwide than today, with Greenland growing crops and running livestock, something not possible even in this latest warming period.

Colder periods have proved disastrous for the human race over the centuries, for example, the 14th-century Black Death occurred after the onset of the Little Ice Age.

• Far from being a pollutant, CO2 is essential and beneficial for plant growth and abundant crops and forests. Earlier periods had far more CO2 in the atmosphere than today, even when there was extreme cold. A doubling of CO2 would make little, if any, difference to the earth's average temperature.

• CO2 in the atmosphere is a tiny percentage (0.001%) of the earth's total which is bound up in the oceans, soil and rocks.

• Concentrations of CO2 vary enormously from place to place. There was more in the atmosphere in 1942 than today - when there was less industrial development - and measurements of CO2 worldwide are unreliable.

The list could go on. But each of the above points needs to be addressed by the well-placed global warming/climate change alarmists who are so keen to spend lots of our tax money and increase living costs to overcome a non-existent problem.

One hopes more of our politicians, media people and academics take the trouble to read Heaven and Earth with open minds. Perhaps the book will empower a few to admit to their nagging "scepticism".

In passing, it was encouraging that a recent US poll found only one third of Americans now believe human CO2 emissions are a significant factor in global warming, a substantial drop from last year.